Field of the Invention
The present invention relates to a motor, and more particularly, to a brushless motor having a stator with an insulating bobbin.
Technology Background
A brushless motor is a motor without a brush and a commutator (or collecting ring). A brushless motor operates by changing the alternating frequency and the wave form of a current wave supplied to the winding coil. Brushless motors are widely used by manufacturers in different sizes because of their high efficiency, low energy consumption, low noise, super long life, high reliability, servo controllability, stepless frequency conversion, speed regulating, low cost, and ease of use.
A brushless motor comprises a casing, a printed circuit board (PCB), a rotor, and a stator. The stator includes an upper insulating bobbin, a stator core, a lower insulating bobbin, and a winding on the stator core defining a plurality of coils. The upper insulating bobbin and the lower insulating bobbin are installed respectively on the upper end face and the lower end face of the stator core. A lead wire winds the coil wound portion, which is formed by an upper slot insulation on the upper insulating bobbin, a tooth portion of the stator core and a lower slot insulation of the lower insulating bobbin as per a certain rule. Thus, the wound lead wire forms a stator winding. The PCB is installed on the upper insulating bobbin and electrically connected to the stator winding.
However, the present inventors have identified a number of problems regarding existing brushless motors.
First, when an insulation displacement connection terminal is used, the terminal fixing block on the upper insulating bobbin is located along the radial direction of the upper insulating bobbin, and the terminal socket on the terminal fixing block is arranged along the circumference direction of the upper insulating bobbin. As a result, the puncture notch of the insulation displacement connection terminal is located along the radial direction of the upper insulating bobbin. Consequently, when the lead wire of the stator winding is winding, the lead wire must be routed out along the radial direction of the upper insulating bobbin, thereby increasing the radial dimension of the stator.
Additionally, each coil of the stator winding needs to be equipped with a terminal, and many terminals are used.
Further, each coil needs to be wound by a piece of lead wire, and all the coil wound portions cannot be wound by a single piece of lead wire. As a result, winding operations are increased.
Moreover, the lead wire is normally routed on single face, which is not convenient for the arrangement of other components. Thus, the dimension of the stator must be increased.